I. Field of the Invention
The present invention relates to a semiconductor device and a manufacturing process thereof and, more particularly, to a semiconductor device including source and drain regions having metal portions and a manufacturing process thereof.
II. Description of the Prior Art
Recently, in a semiconductor device (in particular in a MOSLSI), due to micropatterning, a junction depth of an impurity-diffused wiring including source and drain regions becomes shallower, and a width of the wiring becomes smaller, resulting in a large resistance thereof. For this reason, a method for providing an impurity-diffused wiring having a low resistance in a semiconductor device has become important. In order to solve such a problem, after a gate electrode and source and drain regions are formed, a high-melting point metal silicide is conventionally deposited on respective surfaces of the gate electrode and the source and drain regions, thereby providing a low resistance.
However, a high-melting point metal silicide does not have a sufficiently low resistance in comparison with a metal such as aluminum, and prevents high-speed operation of a MOSLSI. In a method in which the high-melting point metal silicide is deposited after forming the gate electrode and the like, it is difficult to form the gate electrode and the source and the drain regions by self-alignment, thereby preventing high integration of the MOSLSI.